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Button Type Flip Off Seal: The Tamper-Evident FlipTop® Optima Design

Button Type Flip Off Seal | FlipTop® Optima | Autofits

The button type flip off seal is the tamper-evident design in the FlipTop® Optima range: an AA8011 aluminium shell crimped over the rubber stopper, with a polypropylene button whose intrinsic tamper evidence comes from a 12-stem flower formed under the button disc. Once the button is flipped, the opened state is visibly distinct, so tampering cannot be concealed by reseating the button: the evidence is built into the closure itself, not added as a label or band.

This page gives packaging engineers, formulators and quality teams the design explanation, how it differs from the other Optima designs, the sizes and controlled dimensions, materials, quality position, applications and ordering. For the full range, see the FlipTop® Optima product page.

Key takeaways

  • The button type is the FlipTop® Optima design with intrinsic tamper evidence: a 12-stem flower formed under the button disc makes the opened state visibly distinct.
  • Tamper evidence is intrinsic to the closure, with no added label, shrink band or secondary feature to apply on the line.
  • Offered across the Optima size range: 13, 20, 28, 32 and 34 mm, matched to vial necks per ISO 8362-1.
  • Maximum opening force: 30 N (13 mm), 35 N (20 and 28 mm), 65 N (32 mm); the 34 mm value is available on request.
  • Materials: AA8011 aluminium with epoxy lacquer and a polypropylene button moulded in-house on Toyo machines.
  • Made under ISO 15378, ISO 9001 and ISO 14001 with a Drug Master File, assembled in an ISO Class 8 cleanroom, 100% camera inspected.

What is a button type flip off seal?

The button type is a flip-off seal whose tamper evidence is intrinsic: a 12-stem flower is formed under the polypropylene button disc, so once the seal has been opened the closure looks visibly different and cannot be passed off as intact. Like every Optima design, the deep-drawn aluminium shell crimps under the vial neck flange to compress the rubber stopper against the glass, and the button is flipped up at point of use to expose a small central area of the stopper for the needle while the aluminium stays crimped.

Every flip-off seal gives some indication of opening, because the flipped button cannot be restored. The button type goes further by making the evidence a designed, inspectable feature of the closure: the 12-stem flower under the button disc gives the opened seal a distinct appearance that pharmacists, nurses and inspectors can check at a glance. That matters for products where tamper evidence is a specification requirement rather than a side effect, and it removes the need for secondary tamper features that add line steps and materials.

How it differs from the other Optima designs

The Optima top comes in four design variants, all on the same aluminium-plastic construction:

  • Button type (this page): intrinsic tamper evidence via the 12-stem flower under the button disc.
  • Bridge type with groove: the standard tapered-bridge flip-off top with a groove feature that aids a clean crimp and clean button release.
  • Bridge type without groove: the same tapered-bridge top in the plain crown profile.
  • Flower type: the petalled top variant within the Optima range.

If you are weighing the standard bridge construction against the button construction, see the bridge type without groove, which is the standard flip-off top without the intrinsic tamper feature.

Sizes and specifications

The button type follows the controlled Optima dimensions for each neck size, taken from the Autofits engineering drawings. Opening force varies with the number of bridges in the design.

Size Inner Ø alu seal (D1, mm) Outer Ø disc (D2, mm) Total seal height (mm) Alu thickness (mm) Max opening force (N) Standard packing (per box)
13 mm 13.36 (min) 14.99 (max) 7.62–8.38 0.16–0.20 30 15,000 (5,000 × 3 bags)
20 mm 20.22 (min) 23.14 (max) 9.02–9.91 0.16–0.20 35 6,000 (2,000 × 2)
28 mm 27.60–28.20 30.10–31.10 11.06–12.06 0.17–0.23 35 3,000 (1,500 × 2)
32 mm 32.10–32.90 35.50–36.50 14.30–15.50 0.21–0.25 65 1,400 (700 × 2)
34 mm 33.60–34.00 35.50–36.50 15.00–16.00 0.20–0.25 available on request available on request

The standard shipper box is 420 × 270 × 320 mm; Tyvek bagging is available as an alternative to standard polybag packing. Disc height and inner aluminium height for 13 mm are 2.90–3.30 mm and 6.15–6.40 mm; for 20 mm, 3.20–3.60 mm and 7.37–7.62 mm; for 28 mm, inner aluminium height is 8.70–9.30 mm. Remaining per-size heights are available on request. Per-size detail pages: 13mm, 20mm, 28mm, 32mm and 34mm.

Finishes are glossy, matte, embossed or printed, in a wide range of colours, matte or glossy, customised to requirement. Colour coding is commonly combined with the tamper-evident button to differentiate strengths; see the colours page.

Materials and quality

The shell is AA8011 aluminium alloy (EN 15088:2005, EN 10204 3.1 certification, tested to BS EN 485-2:2008; REACH and RoHS compliant) with an epoxy lacquer coating to 21 CFR 175.300, which may be pigmented for colour. The button is polypropylene to IS 10910 / IS 10909 and FDA 21 CFR 177.1520, moulded in-house on Japanese Toyo injection-moulding machines, which keeps the button and tamper-evidence geometry consistent batch to batch. Heavy metals (chrome-VI, cadmium, mercury, lead) are held to a maximum 100 ppm total, and components are BSE/TSE-free per EMEA/410/01 rev. 3.

Components are washed on a fully automated line to control particulates, assembled in an ISO Class 8 cleanroom, and every seal passes 100% high-speed camera inspection before packing. Production runs under ISO 15378:2017 GMP with ISO 9001:2015 and ISO 14001:2015 certification, a Drug Master File (DMF 18100) and CFDA registration, at the Autofits Packaging Pvt. Ltd. 75,000 sq ft facility in Nashik, India. The design follows ISO 8362-6 for aluminium-plastics combination caps; the quality system is described under ISO 15378. AQL: critical nil, major not more than 2.5%, minor not more than 4%, tailorable to customer specification.

Applications

Specify the button type wherever the closure itself must demonstrate tamper evidence: controlled substances, high-value injectables, vaccines, biologics and any specification that names an intrinsic tamper-evident closure. It runs on the same capping equipment as the other Optima designs, so upgrading a product from a standard bridge top to the tamper-evident button is a component change rather than a line change. For routine products without a tamper-evidence requirement, the bridge type covers the need. Browse comparable closures on the by-size index.

Forms of supply and ordering

The button type ships Regular (non-sterile), Ready-to-Use (RTU: assembled in the ISO Class 8 cleanroom, double-lacquered aluminium, washed to control particulates, then gamma irradiated or ETO sterilized, supplied double-bagged for aseptic areas) and Ready-to-Sterilize (RTS). Shelf life is 3.5 years before capping for non-irradiated seals (plus 5 years after capping) and 2 years before capping for RTU.

To order, contact Autofits with your size, the button design, finish, colour reference and required form of supply. Minimum order quantities and lead times are available on request.

Frequently asked questions

What is a button type flip off seal?

It is the tamper-evident design in the FlipTop® Optima range. A 12-stem flower is formed under the polypropylene button disc, so once the button is flipped the opened state is visibly distinct and cannot be concealed. The aluminium shell stays crimped on the vial and the injection point is exposed as with any flip-off seal.

How does the button type give tamper evidence?

The tamper evidence is intrinsic: the 12-stem flower under the button disc is part of the closure’s construction, so an opened seal looks unmistakably different from an intact one. No label, shrink band or secondary feature is needed.

How is the button type different from a bridge type seal?

The bridge type is the standard flip-off top and does not carry the intrinsic tamper-evidence feature. The button type adds the 12-stem flower under the button disc for designed, inspectable tamper evidence. See the bridge type without groove for the standard flip-off top.

What sizes does the button type come in?

It is offered across the Optima range: 13, 20, 28, 32 and 34 mm neck sizes, matched to the vial finish and stopper of the same nominal diameter. Vial necks follow ISO 8362-1.

What is the opening force of the button type?

Maximum opening force follows the Optima size: 30 N for 13 mm, 35 N for 20 mm and 28 mm, and 65 N for 32 mm; force varies with the number of bridges in the design. The 34 mm value is available on request.

Is the button type available sterilized?

Yes. It is offered Ready-to-Use, sterilized by gamma irradiation or ETO and supplied double-bagged for aseptic filling, as well as Ready-to-Sterilize and Regular. RTU seals are washed and assembled in an ISO Class 8 cleanroom.

Does the button type need different capping equipment?

No. It is crimped like the other Optima designs, so switching a product from a bridge top to the tamper-evident button is a component specification change, not a line change. Confirm the fit against your vial finish and stopper as part of normal component qualification.

Related reading

Sources

  • Autofits FlipTop Seals dossier and engineering drawings (working/spec-sheets/)
  • ISO: ISO 8362-6:2010, Caps made of aluminium-plastics combinations for injection vials (https://www.iso.org/standard/45641.html)

*Last updated: 2026-07-06. This page is general technical and product information, not regulatory or compliance advice; confirm current standard editions and your own specification with Autofits and the issuing bodies.*

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